New research finds that caterpillars commercially bred as fishing bait also have the ability to break down polyethylene, one of the most common and resilient plastics. Scientists think the new finding could be a groundbreaking biodegradable solution to the problem of plastic bags.

The discovery came about not in a lab, but by chance discovery at the home of Federica Bertocchini, a researcher at Spain’s Institute of Biomedicine and Biotechnology of Cantabria.

Bertocchini, who’s also an amateur beekeeper, found the wax worms, who live off beeswax, has infested her beehives. The scientist removed the worms and placed them in a plastic bag, only to discover they had eaten quickly eaten their way out, Science Magazine reports.

Wax worm specimens in a Petri dish. (César Hernández/CSIC)

After testing this in a lab, the researchers learned that wax worms break down polyethylene into ethylene glycol—a substance that can easily be converted into something useful like antifreeze.

Polyethylene is notorious for being difficult to biodegrade. Despite this, 80 tons of it are produced annually, creating a challenge for recycling and trash disposal. In their findings, published in Current Biology, researchers say wax worms could be a unexpected green solution to a longtime sustainability problem.